An analysis of mineral grains from the bottom of the western Grand Canyon indicates it was largely carved out by about 70 million years ago -- a time when dinosaurs were around and may have even peeked over the rim, says a study led by the University of Colorado Boulder.

The new research pushes back the conventionally accepted date for the formation of the Grand Canyon in Arizona by more than 60 million years, said CU-Boulder Assistant Professor Rebecca Flowers. The team used a dating method that exploits the radioactive decay of uranium and thorium atoms to helium atoms in a phosphate mineral known as apatite, said Flowers, a faculty member in CU-Boulder's geological sciences department.

The helium atoms were locked in the mineral grains as they cooled and moved closer to the surface during the carving of the Grand Canyon, she said. Temperature variations at shallow levels beneath the Earth's surface are influenced by topography, and the thermal history recorded by the apatite grains allowed the team to infer how much time had passed since there was significant natural excavation of the Grand Canyon, Flowers said.

"Our research implies that the Grand Canyon was directly carved to within a few hundred meters of its modern depth by about 70 million years ago," said Flowers. A paper on the subject by Flowers and Professor Kenneth Farley of the California Institute of Technology was published online Nov. 29 in Science magazine.

Flowers said there is significant controversy among scientists over the age and evolution of the Grand Canyon. A variety of data suggest that the Grand Canyon had a complicated history, and the entire modern canyon may not have been carved all at the same time. Different canyon segments may have evolved separately before coalescing into what visitors see today.

In a 2008 study, Flowers and colleagues showed that parts of the eastern section of the Grand Canyon likely developed some 55 million years ago, although the bottom of that ancient canyon was above the height of the current canyon rim at that time before it subsequently eroded to its current depth.

Over a mile deep in places, Arizona's steeply sided Grand Canyon is about 280 miles long and up to 18 miles wide in places. Visited by more than 5 million people annually, the iconic canyon was likely carved in large part by an ancestral waterway of the Colorado River that was flowing in the opposite direction millions of years ago, said Flowers.

"An ancient Grand Canyon has important implications for understanding the evolution of landscapes, topography, hydrology and tectonics in the western U.S. and in mountain belts more generally," said Flowers. The study was funded in part by the National Science Foundation.

Whether helium is retained or lost from the individual apatite crystals is a function of temperatures in the rocks of Earth's crust, she said. When temperatures of the apatite grains are greater than 158 degrees Fahrenheit, no helium is retained in the apatite, while at temperatures below 86 degrees F, all of the helium is retained.

"The main thing this technique allows us to do is detect variations in the thermal structure at shallow levels of the Earth's crust," she said. "Since these variations are in part induced by the topography of the region, we obtained dates that allowed us to constrain the timeframe when the Grand Canyon was incised."

Flowers and Farley took their uranium/thorium/helium dating technique to a more sophisticated level by analyzing the spatial distribution of helium atoms near the margin of individual apatite crystals. "Knowing not just how much helium is present in the grains but also how it is distributed gives us additional information about whether the rocks had a rapid cooling or slow cooling history," said Flowers.

While processes of evolution are largely studied by observation and experiment in the living world, evolutionary tempo and mode – rates and patterns of change, respectively – are mostly revealed by studying the fossil record. Paleontologists measure parts of the hard skeletal fossil remains of once-living organisms that they believe best represent the morphology, or form, of those organisms. They then analyze the variation in these traits through successive layers of rock that were laid down over longs spans of geologic time in order to determine the tempo and mode of species evolution. Punctuated equilibrium postulates that most evolutionary change takes place in relatively short periods of time during the origination of new species, while species themselves mostly undergo stasis, or little change, over longer periods. Several recent studies have indicated that stasis is much more common than gradual directional change in the fossil record. Mosaic evolution, on the other hand, is the tendency for different parts within species to evolve in different ways or at different rates.

The new study is based on data taken from hundreds of sequences of fossil samples previously reported in the scientific literature, but uses model selection methods available only in the last several years. The researchers compared models describing different modes of change, namely stasis, random change, and directional change, to each fossil series and found that different traits generally showed different, conflicting evolutionary modes within the same species. Many kinds of life were represented, including mammals, fish, mollusks, arthropods, and single-celled organisms. This large comparative study validates the ubiquity of mosaic evolution. However, it also raises questions about the evidence for different evolutionary modes, since the great majority of previous studies that quantify stasis, punctuated equilibrium, and gradual or "random" patterns in the fossil record are based on measurements of single traits, not on combined analyses of many traits. Further research will be required to establish the underlying processes driving the patterns of mosaic evolution and fossil species change. Nonetheless, the study is an excellent example of an emerging revolution in scientific inquiry as new techniques are used to breathe new life into old data.

Astronomers find planets in strange places and wonder if they might support life. One such place would be in orbit around a white or brown dwarf. While neither is a star like the sun, both glow and so could be orbited by planets with the right ingredients for life.

No terrestrial, or Earth-like planets have yet been confirmed orbiting white or brown dwarfs, but there is no reason to assume they don’t exist. However, new research by Rory Barnes of the University of Washington and René Heller of Germany’s Leibniz Institute for Astrophysics Potsdam hints that planets orbiting white or brown dwarfs will prove poor candidates for life.

White dwarfs are the hot cores of dead stars and brown dwarfs are failed stars, objects not massive enough to start nuclear burning as the sun does. In theory, both can be bright enough to theoretically support a habitable zone — that swath of space just right for an orbiting planet’s surface water to be in liquid form, thus giving life a chance.

The inner edge of that just-right zone is where a planet starts to become a runaway greenhouse, such as Venus. That heating phenomenon removes the planet’s surface water and all chance of life — of habitability — is forever lost.

White and brown dwarfs share a common characteristic that sets them apart from normal stars like the sun: They slowly cool and become less luminous over time. And as they cool, their habitable zones gradually shrink inward. Thus, a planet that is found in the center of the habitable zone today must previously have spent time near the zone’s deadly inner edge.

Because of their past, such planet would “face a difficult path to habitability,” Barnes said, even if they’re discovered right in that habitable zone. Call it a sort of cosmic background check, revealing that the worlds probably lost the means to host life long before they became habitable zone residents.

The Israeli military is developing a large, classified unmanned air vehicle (UAV) with features consistent with stealthy aircraft designs, according to a knowledgable source.

The secret project involves a "fairly large" UAV in development by Israel Aerospace Industries (IAI), the maker of the non-stealthy Heron and Eitan (which is called the Heron TP for export) UAVs, the source says.

Israel has been openly involved with stealth and minimal-detection programmes. Experts familiar with Israeli industry profess little surprise in a low-observable aircraft capability.

"There have been rumours about it, and you see Israeli companies have rolled out an array of products across the spectrum," says a former US government official. "You would expect that stealth is something they'd be interested in, particularly in light of the threats they face."

Israel, a small nation surrounded by largely hostile neighbors, has long placed an emphasis on operating in denied areas with various means. Recent airstrikes thought to involve Israel include a 2007 strike that destroyed a nuclear plant in Syria, and two more recent strikes on targets deep in Sudanese territory. Operations over denied airspace, particularly airspace protected by sophisticated surface-to-air networks, require both stealth and endurance.

"I know that they were working on small and medium-size variants [of stealth aircraft] for some years now," says one industry analyst, who declined to comment on the record. According to the analyst, IAI has been working on stealth technologies since the mid-1990s or earlier.

Terrestrial herbivorous tetrapods first appear in the fossil record during the Late Carboniferous (306.5 Ma). The diversification of herbivores is a key aspect of the transition to the modern trophic structure of terrestrial vertebrate ecosystems, because it allowed tetrapods to exploit terrestrial (i.e. non-aquatic) primary productivity. However, the palaeodiversity dynamics of the earliest terrestrial vertebrate herbivores have received relatively little attention, apart from a few studies that focus on specific clades. A new data set containing 287 species occurrences of herbivorous tetrapods including the major Palaeozoic and Early Triassic clades Anomodontia, Archosauromorpha, Bolosauridae, Captorhinidae, Caseidae, Cynodontia, Dinocephalia, Diadectomorpha, Edaphosauridae, Pareiasauria, Poposauroidea, Procolophonoidea, Rhynchosauria, Silesauridae and Therocephalia is used to analyse palaeodiversity from the Late Carboniferous to the Middle Triassic (~ 306.5 – ~ 236 Ma), taking into account the effects of potential sampling biases by using the number of tetrapod-bearing formations as a proxy. The results support a gradual increase in taxic diversity from the Late Carboniferous to the Wordian, followed by a dip in diversity during the Guadalupian (Middle Permian), and an increase to a peak in the Late Permian at the Wuchiapingian/Changhsingian boundary. Herbivorous tetrapods were strongly affected by the end-Permian mass extinction with both the herbivorous Pareiasauria and Captorhinidae becoming extinct and the observed number of anomodont species decreasing by up to 80%. The drop in observed diversity at the end Permian is dampened slightly because of the radiation of new herbivorous forms during the Early Triassic. A strong biological signal is apparent even after correcting for sampling.

They use the "Land Vertebrate Faunachrons", which I thought were considered flawed.

Sooo...not sure what the accuracy of this is. I Am Not a Triassic (or any really) Paleontologist though.

Krishna Chandra Yadav, director, State Forest Research and Training Institute (SFRTI) in Raipur, and colleagues announced the discoveries of the oldest know fossilized trees ever found in India in the November, 26, 2012, issue of the Indian Express.

The fossilized gymnosperms were scattered across a 700 hectares area of the Shankarpur, Bhattidarh, Thadadpahri, and Naginjhiria villages of the Surajpur district on the northern fringe of Tamor Pingla Wildlife Sanctuary.

The 250 million years Triassic fossil trees measured as large as 15 meters in length and eight meters in diameter. Many of the stones (fossil trees) were so large local villagers had used the fossils as building materials for their homes and farm buildings. Previous fossil trees in India have been found that were 50 million years old.

Researchers from Birbal Sahni Institute of Palaeobotany in Lucknow confirmed the discovery.

Um. That tree diameter sounds like a journalistic oops. However, it'd be an exciting site to work because of the fact the Induan is right after the PT Extinction. A petrified forest of India sounds awesome.

On the basis of geological evidence, it is often stated that the early martian climate was warm enough for liquid water to flow on the surface thanks to the greenhouse effect of a thick atmosphere. We present 3D global climate simulations of the early martian climate performed assuming a faint young sun and a CO2 atmosphere with pressure between 0.1 and 7 bars. The model includes a detailed radiative transfer model using revised CO2 gas collision induced absorption properties, and a parameterisation of the CO2 ice cloud microphysical and radiative properties. A wide range of possible climates is explored by using various values of obliquities, orbital parameters, cloud microphysic parameters, atmospheric dust loading, and surface properties. Unlike on present day Mars, for pressures higher than a fraction of a bar, surface temperatures vary with altitude because of the adiabatic cooling and warming of the atmosphere when it moves vertically. In most simulations, CO2 ice clouds cover a major part of the planet but greenhouse effect does not exceed +15 K. We find that a CO2 atmosphere could not have raised the annual mean temperature above 0 C anywhere on the planet. The collapse of the atmosphere into permanent CO2 ice caps is predicted for pressures higher than 3 bar, or conversely at pressure lower than one bar if the obliquity is low enough. Summertime diurnal mean surface temperatures above 0{\deg}C (a condition which could have allowed rivers to form) are predicted for obliquity larger than 40{\deg} at high latitudes but not in locations where most valley networks are observed. In the absence of other warming mechanisms, our climate model results are thus consistent with a cold early Mars scenario in which non climatic mechanisms must occur to explain the evidence for liquid water. In a companion paper by Wordsworth et al., we simulate the hydrological cycle on such a planet.

Using ESA's Herschel space observatory, astronomers have discovered vast comet belts surrounding two nearby planetary systems known to host only Earth-to-Neptune-mass worlds. The comet reservoirs could have delivered life-giving oceans to the innermost planets.

In a previous Herschel study, scientists found that the dusty belt surrounding nearby star Fomalhaut must be maintained by collisions between comets.

In the new Herschel study, two more nearby planetary systems – GJ 581 and 61 Vir – have been found to host vast amounts of cometary debris.

Herschel detected the signatures of cold dust at 200ºC below freezing, in quantities that mean these systems must have at least 10 times more comets than in our own Solar System's Kuiper Belt.

GJ 581, or Gliese 581, is a low-mass M dwarf star, the most common type of star in the Galaxy. Earlier studies have shown that it hosts at least four planets, including one that resides in the 'Goldilocks Zone' – the distance from the central sun where liquid surface water could exist.

Two planets are confirmed around G-type star 61 Vir, which is just a little less massive than our Sun.

The planets in both systems are known as 'super-Earths', covering a range of masses between 2 and 18 times that of Earth.

Interestingly, however, there is no evidence for giant Jupiter- or Saturn-mass planets in either system.

The gravitational interplay between Jupiter and Saturn in our own Solar System is thought to have been responsible for disrupting a once highly populated Kuiper Belt, sending a deluge of comets towards the inner planets in a cataclysmic event that lasted several million years.

"The new observations are giving us a clue: they're saying that in the Solar System we have giant planets and a relatively sparse Kuiper Belt, but systems with only low-mass planets often have much denser Kuiper belts," says Dr Mark Wyatt from the University of Cambridge, lead author of the paper focusing on the debris disc around 61 Vir.

"We think that may be because the absence of a Jupiter in the low-mass planet systems allows them to avoid a dramatic heavy bombardment event, and instead experience a gradual rain of comets over billions of years."

Tuesday, November 27, 2012

Every kid knows that giant carnivores like Tyrannosaurus rex dominated the Cretaceous period, but they weren't the only big guys in town. Giant plant-eating theropods – close relatives of both T. rex and today's birds – also lived and thrived alongside their meat-eating cousins. Now researchers have started looking at why dinosaurs that abandoned meat in favor of vegetarian diets got so big, and their results may call conventional wisdom about plant-eaters and body size into question.

Scientists have theorized that bigger was better when it came to plant eaters, because larger digestive tracts would allow dinosaurs to maximize the nutrition they could extract from high-fiber, low-calorie food. Therefore, natural selection may have favored increasing body sizes in groups of animals that went meatless.

Three groups of giant feathered theropods from the Cretaceous period seemed to follow that rule of thumb – the biggest specimens were also the plant-eaters. Lindsay Zanno, research assistant professor of biology at North Carolina State University and director of the Paleontology; Geology Research Lab at the North Carolina Museum of Natural Sciences, and Peter Makovicky, associate curator of paleontology at the Field Museum in Chicago, decided to see if diet was the determining factor when it came to size. Makovicky notes that "Having three closely related lineages of dinosaurs adapting to herbivory over the same geological time span and showing evidence of increasing size provided a near perfect test case."

Zanno and Makovicky estimated body mass for 47 extinct species of feathered dinosaur, representing three major groups that abandoned a strictly meat-eating diet – ornithomimosaurs ("bird-mimics"), oviraptorosaurs ("egg-thieves"), and the bizarre therizinosaurs ("scythe-lizards"). Most species in these lineages also possessed a toothless beak, three-toed feet, and shorter tails than your average dinosaur, making them look a lot like modern birds.

All three groups evolved gigantic proportions: the largest oviraptorosaur weighed over 7,000 pounds, and the biggest ornithomimosaurs and therizinosaurs topped out at over 13,000 pounds. "The largest feathered dinosaurs were more than 100 times more massive than your average person," says Zanno. "The reality is that for most of us, it is downright difficult to imagine a feathered animal of gigantic proportions."

The researchers also found that average body mass did increase in these groups over time (on average, the earliest members were smallest and the last species to evolve were among the largest). But this simple correlation didn't indicate whether large size was an evolutionary advantage.

To test whether these groups were being driven to get bigger by natural selection, Zanno and Makovicky fitted different evolutionary models to the data, looking to see which model best described the patterns of body mass from ancestor species to descendant species. They found that these theropod groups were experimenting with different body masses as they evolved, with some getting bigger, while others were getting smaller. In short, there was no clear-cut drive to get big – size seemed to provide no overwhelming advantage during the evolution of these animals.

The researchers' results appear in Proceedings of the Royal Society B.

"Results of our study don't rule out diet as affecting body mass, but do seem to indicate that fluctuating environmental conditions over time were trumping the benefit of becoming a giant," Zanno says. "The long and short of it is that for plant-eating theropods, bigger wasn't always better."

A star is slowly snuffing the life out of an alien planet. But in a macabre twist, material stripped out of the dying world's atmosphere has become a death shroud enveloping the gas giant and its star.

First discovered in 2008, WASP-12b is a so-called hot Jupiter—a gas giant planet orbiting extremely close to its parent star.

Located 1,100 light-years away, WASP-12b hugs its star so tightly that a year on the planet lasts just over one Earth day. The two objects are so close that scientists think that the gas that makes up most of the doomed planet is being boiled off and blown into space by the intense heat from its star.

"At the current best guess ... the planet will lose most of its mass in about one billion years," said astrophysicist Carole Haswell of The Open University in the United Kingdom. A relative blink of an eye when compared to Earth's projected 9-billion-year life span.

Dwarf planet Makemake is about two thirds of the size of Pluto, and travels around the Sun in a distant path that lies beyond that of Pluto but closer to the Sun than Eris, the most massive known dwarf planet in the Solar System. Previous observations of chilly Makemake have shown it to be similar to its fellow dwarf planets, leading some astronomers to expect its atmosphere, if present, to be similar to that of Pluto. However, the new study now shows that, like Eris, Makemake is not surrounded by a significant atmosphere.

The team, led by Jose Luis Ortiz (Instituto de Astrofisica de Andalucia, CSIC, Spain), combined multiple observations using three telescopes at ESO's La Silla and Paranal observing sites in Chile -- the Very Large Telescope (VLT), New Technology Telescope (NTT), and TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) -- with data from other small telescopes in South America, to look at Makemake as it passed in front of a distant star.

"As Makemake passed in front of the star and blocked it out, the star disappeared and reappeared very abruptly, rather than fading and brightening gradually. This means that the little dwarf planet has no significant atmosphere," says Jose Luis Ortiz. "It was thought that Makemake had a good chance of having developed an atmosphere -- that it has no sign of one at all shows just how much we have yet to learn about these mysterious bodies. Finding out about Makemake's properties for the first time is a big step forward in our study of the select club of icy dwarf planets."

Makemake's lack of moons and its great distance from us make it difficult to study, and what little we do know about the body is only approximate. The team's new observations add much more detail to our view of Makemake -- determining its size more accurately, putting constraints on a possible atmosphere and estimating the dwarf planet's density for the first time. They have also allowed the astronomers to measure how much of the Sun's light Makemake's surface reflects -- its albedo. Makemake's albedo, at about 0.77, is comparable to that of dirty snow, higher than that of Pluto, but lower than that of Eris.

Academics at the Universities of Bristol, Yale and Calgary have shown that prehistoric birds had a much more primitive version of the wings we see today, with rigid layers of feathers acting as simple airfoils for gliding.

Close examination of the earliest theropod dinosaurs suggests that feathers were initially developed for insulation, arranged in multiple layers to preserve heat, before their shape evolved for display and camouflage.

As evolution changed the configuration of the feathers, their important role in the aerodynamics and mechanics of flight became more apparent. Natural selection over millions of years ultimately modified dinosaurs' forelimbs into highly-efficient, feathered wings that could rapidly change its span, shape and area – a key innovation that allowed dinosaurs to rule the skies.

This basic wing configuration has remained more or less the same for the past 130 million years, with bird wings having a layer of long, asymmetrical flight feathers with short covert feathers on top. They are able to separate and rotate these flight feathers to gain height, change direction and even hover.

This formation allows birds to move in such a way as to produce both lift and thrust simultaneously – a capability that man, with the help of technology, is still trying to successfully imitate.

The research, published today [21 November] in Current Biology, looked at the dinosaur Anchiornis huxleyi and the Jurassic bird Archaeopteryx lithographica. The latter is 155 million years old and widely considered to be the earliest known bird, presenting a combination of dinosaur and bird characteristics.

Their wings differed from modern day birds in being composed of multiple layers of long feathers, appearing to represent early experiments in the evolution of the wing. Although individual feathers were relatively weak due to slender feather shafts, the layering of these wing feathers is likely to have produced a strong airfoil.

The inability to separate feathers suggests that taking off and flying at low speeds may have been limited, meaning that wings were primarily used in high-speed gliding or flapping flight.

Dr Jakob Vinther, from the University of Bristol's Schools of Biological and Earth Sciences, said: "We are starting to get an intricate picture of how feathers and birds evolved from within the dinosaurs. We now seem to see that feathers evolved initially for insulation. Later in evolution, more complex vaned or pinnate feathers evolved for display.

I was under the impression that feathers were for display first and then insulation was the side benefit. Well, this will be one of those fights that's not resolved for years at best. I am hoping its not theory advancement by attrition.

*. To whom correspondence should be addressed. E-mail: onoue@sci.kagoshima-u.ac.jp.Abstract:

The 34-million-year (My) interval of the Late Triassic is marked by the formation of several large impact structures on Earth. Late Triassic impact events have been considered a factor in biotic extinction events in the Late Triassic (e.g., end-Triassic extinction event), but this scenario remains controversial because of a lack of stratigraphic records of ejecta deposits. Here, we report evidence for an impact event (platinum group elements anomaly with nickel-rich magnetite and microspherules) from the middle Norian (Upper Triassic) deep-sea sediment in Japan. This includes anomalously high abundances of iridium, up to 41.5 parts per billion (ppb), in the ejecta deposit, which suggests that the iridiumenriched ejecta layers of the Late Triassic may be found on a global scale. The ejecta deposit is constrained by microfossils that suggest correlation with the 215.5-Mya, 100-km-wide Manicouagan impact crater in Canada. Our analysis of radiolarians shows no evidence of a mass extinction event across the impact event horizon, and no contemporaneous faunal turnover is seen in other marine planktons. However, such an event has been reported among marine faunas and terrestrial tetrapods and floras in North America. We, therefore, suggest that the Manicouagan impact triggered the extinction of terrestrial and marine organisms near the impact site but not within the pelagic marine realm.

The early Miocene mammal Necrolestes patagonensis from Patagonia, Argentina, was described in 1891 as the only known extinct placental “insectivore” from South America (SA). Since then, and despite the discovery of additional well-preserved material, the systematic status of Necrolestes has remained in flux, with earlier studies leaning toward placental affinities and more recent ones endorsing either therian or specifically metatherian relationships. We have further prepared the best-preserved specimens of Necrolestes and compared them with newly discovered nontribosphenic Mesozoic mammals from Argentina; based on this, we conclude that Necrolestes is related neither to marsupials nor placentals but is a late-surviving member of the recently recognized nontherian clade Meridiolestida, which is currently known only from SA. This conclusion is supported by a morphological phylogenetic analysis that includes a broad sampling of therian and nontherian taxa and that places Necrolestes within Meridiolestida. Thus, Necrolestes is a remnant of the highly endemic Mesozoic fauna of nontribosphenic mammals in SA and extends the known record of meridiolestidans by almost 45 million years. Together with other likely relictual mammals from earlier in the Cenozoic of SA and Antarctica, Necrolestes demonstrates the ecological diversity of mammals and the mosaic pattern of fauna replacement in SA during the Cenozoic. In contrast to northern continents, the Cenozoic faunal history of SA was characterized by a long period of interaction between endemic mammalian lineages of Mesozoic origin and metatherian and eutherian lineages that probably dispersed to SA during the latest Cretaceous or earliest Paleocene.

Monday, November 19, 2012

As much as the resources wielded by the Chinese state aerospace industry impress outsiders these days, few could have expected that one of the companies in the sector would want to produce a stealth fighter on its own account.

But that is just what Shenyang Aircraft wants to do. Equally surprisingly, the Chinese air force is turning its nose up at the result. What looks like a thoroughly modern stealth fighter is apparently not good enough to serve as China's next medium-weight combat aircraft.

After three evidently staged appearances of the real aircraft this year, Avic displayed a model at Airshow China in Zhuhai last week, displaying the fighter that is unofficially called the J-31 and known to come from Shenyang. The aircraft is being developed “for the international defense market,” says Avic.

The model was labeled as a concept fighter, but it showed few if any differences from the real aircraft that appeared first under wraps on a truck in June, then being pulled around an airfield in September and, finally, on Oct. 31, in the air, prominently numbered “31001” and possibly making its first flight. It is clear, then, that the project has transcended the concept stage.

The aircraft has been designed to deliver a highly stealthy configuration at low cost, with a heavy weapons load capability over a wide combat radius, says Avic. The model is a single-seat, twin-tail, twin-engine aircraft with a high wing, like the real aircraft seen in unattributed photographs on the Internet. As described at the show, the fighter has a typical takeoff weight of 17.5 metric tons, is 16.9 meters (55.5 ft.) long and 4.8 meters high with a wingspan of 11.5 meters.

The aircraft that flew last month has two Klimov RD-93 engines, which project engineers do not regard as sufficiently powerful, industry executives say. As fitted to the JF-17 (or FC-1) single-engine export fighter from Shenyang's rival, Chengdu Aircraft, the RD-93 produces 19,000 lb. thrust. Regardless of the RD-93's power, Shenyang needs a Chinese engine if it is to avoid Russia holding a veto over J-31 sales. Judging from photographs of the prototype, the nacelles may be designed for engines larger in diameter than the RD-93, a derivative of the MiG-29's RD-33. The alternative may be the reported WS-13 Taishan from the Guizhou plant of propulsion specialist Avic Engine.

"Even though the Norse are traditionally thought of as farmers, they adapted quickly to the Arctic environment and the unique hunting opportunities. During the period they were in Greenland, the Norse ate gradually more seals. By the 14th century, seals made up between 50 and 80 per cent of their diet."

The Danish and Canadian researchers are studying the 80 Norse skeletons kept at the University of Copenhagen's Laboratory of Biological Anthropology in order to determine their dietary habits. From studying the ratio of the isotopes carbon-13 and carbon-15, the researchers determined that a large proportion of the Greenlandic Norse diet came from the sea, particularly from seals. Heinemeier measured the levels of carbon isotopes in the skeletons, Erle Nelson of Simon Fraser University, in Vancouver, Canada, analysed the isotopes, while Niels Lynnerup of the University of Copenhagen, examined the skeletons.

"Nothing suggests that the Norse disappeared as a result of a natural disaster. If anything they might have become bored with eating seals out on the edge of the world. The skeletal evidence shows signs that they slowly left Greenland. For example, young women are underrepresented in the graves in the period toward the end of the Norse settlement. This indicates that the young in particular were leaving Greenland, and when the numbers of fertile women drops, the population cannot support itself," Lynnerup explains.

Not as "romantic" to be sure, but I think that the farming communities of the US have some sympathy with this.

In a rare direct photo of a world beyond Earth, astronomers have spotted a planet 13 times more massive than Jupiter, the largest planet in our own solar system.

The planet orbits a star called Kappa Andromedae that is 2.5 times the mass of the sun and is located 170 light-years away from Earth. As a gas giant larger than Jupiter, it's classified as a "super-Jupiter."

The object is an interesting test case for theories of planet formation, scientists say. Based on observations of this system, the super Jupiter appears to have formed in the same way ordinary, lower-mass exoplanets do, by coalescing from a "protoplanetary disk" of material orbiting a nascent star.

That's because its orbit, somewhat wider than the path Neptune takes around our sun, is at a comparable distance to planetary orbits in the solar system. Additionally, its star, kappa Andromedae, is relatively young, at about 30 million years old (for comparison, the sun is roughly 5 billion years old). These clues point toward a formation story typical of smaller planets.

Previously, some scientists had doubted that such large stars could give birth to planets in protoplanetary disks. The new finding indicates that this star probably did just that.

Doswellia sixmilensis is a new species of the doswelliid archosauromorph genus Doswellia named for an incomplete skeleton from the Upper Triassic Bluewater Creek Formation of the Chinle Group in west-central New Mexico, USA. D. sixmilensis differs from D. kaltenbachi Weems, the type and only other known species of Doswellia, in its larger size, higher tooth count and greater heterodonty, possession of keels on the cervical centra and the presence of discrete knobs or spikes on some osteoderms. The holotype of D. sixmilensis is the fourth occurrence of Doswellia and only the second occurrence of a Doswellia skull, which includes the previously unknown premaxilla and maxilla (and therefore the best dentition) and has the best-preserved cervical vertebrae. Although it adds to our knowledge of the anatomy of Doswellia, this new information does not alter previous concepts of the phylogenetic relationships of the doswelliid genera, largely because they are so poorly known anatomically. The genus Doswellia is known from the Newark Supergroup in Virginia, and the Chinle Group in Texas, New Mexico and Utah, in strata of Otischalkian–Adamanian age. The type locality of D. sixmilensis is c. 43 m stratigraphically below a bed from which U-Pb dating of detrital zircons yields a maximum depositional age of c. 220 Ma, so this is a reasonable approximate numerical age for D. sixmilensis.

A University of Toronto-led team of anthropologists has found evidence that human ancestors used stone-tipped weapons for hunting 500,000 years ago – 200,000 years earlier than previously thought.

"This changes the way we think about early human adaptations and capacities before the origin of our own species," says Jayne Wilkins, a PhD candidate in the Department of Anthropology at the University of Toronto and lead author of a new study in Science. "Although both Neandertals and humans used stone-tipped spears, this is the first evidence that the technology originated prior to or near the divergence of these two species," says Wilkins.

Attaching stone points to spears – known as 'hafting' – was an important advance in hunting weaponry for early humans. Hafted tools require more effort and foreplanning to manufacture, but a sharp stone point on the end of a spear can increase its killing power.

Hafted spear tips are common in Stone Age archaeological sites after 300,000 years ago. This new study shows that they were also used in the early Middle Pleistocene, a period associated with Homo heidelbergensis and the last common ancestor of Neandertals and modern humans.

"It now looks like some of the traits that we associate with modern humans and our nearest relatives can be traced further back in our lineage", Wilkins says.

c. Centres of Exploration Targeting and Biogeochemistry, School of Earth and Environment, University of Western Australia, Perth, WA 6009, Australia

Abstract:

Photic zone euxinia (PZE) has proven important for elucidating biogeochemical changes that occur during oceanic anoxic events, including mass extinction and conditions associated with unique fossil preservation. Organic geochemical analyses of a 380 Ma invertebrate fossil, which included well-preserved soft tissues, from the Gogo Formation (Canning Basin, Western Australia) showed biomarkers and stable isotopic values characteristic of PZE and a consortium of sulfate-reducing bacteria, which lead to exceptional fossil and biomarker preservation. The carbonate concretion contained phytoplankton, green sulfur bacteria (Chlorobi), and sulfate-reducing bacteria biomarkers with an increasing concentration toward the nucleus where the fossil is preserved. The spatial distribution of cholestane unequivocally associated with the fossilized tissue and its high relative abundance to the total steranes suggest that the fossil is a crustacean. The presence of an active sulfur cycle in this Devonian system, including sulfate reduction and the resulting PZE, played a pivotal role in the preservation of soft tissue from the fossil and its associated low-maturity biomarker ratios.

c. College of Naturopathic Medicine, University of Bridgeport, Bridgeport, Connecticut, USA

Abstract:

Two giant partial bone shafts, possible femora, from the Rhaetian Bone Bed (Upper Triassic) of Aust Cliff in SW England continue to conceal their origin. The most striking characteristic of these bones is their size, showing that dinosaur-like gigantism had already evolved by the Late Triassic. Based on their characteristic, columnar shaft morphology, Galton (2005) suggested they came from a prosauropod or stegosaur. The bone histology of both specimens is very similar: the cortex is always rather thin, not exceeding 10 mm, and is of fibrolamellar type with longitudinal primary osteons. The primary osteons show a rather unusual feature, the development of a secondary osteon inside the primary one. The bone surface in both specimens shows open vascular canals, suggesting that the animals were still growing at the time of death, but an external fundamental system (EFS) is visible in the outermost cortex of specimen BRSMG Cb3870. The external cortex shows dense growth marks, but their annual nature is difficult to ascertain. The bones are probably dinosaurian, as indicated by the fibrolamellar bone, and possibly belong to an unknown basal sauropodomorph lineage. Alternatively, some very large pseudosuchians may have evolved fibrolamellar bone independently as an adaptation for reaching giant size.

Wednesday, November 14, 2012

Astronomers using ESO's Very Large Telescope and the Canada-France-Hawaii Telescope have identified a body that is very probably a planet wandering through space without a parent star. This is the most exciting free-floating planet candidate so far and the closest such object to the Solar System at a distance of about 100 light-years. Its comparative proximity, and the absence of a bright star very close to it, has allowed the team to study its atmosphere in great detail. This object also gives astronomers a preview of the exoplanets that future instruments aim to image around stars other than the Sun.

Free-floating planets are planetary-mass objects that roam through space without any ties to a star. Possible examples of such objects have been found before [1], but without knowing their ages, it was not possible for astronomers to know whether they were really planets or brown dwarfs -- "failed" stars that lack the bulk to trigger the reactions that make stars shine.

But astronomers have now discovered an object, labelled CFBDSIR2149 [2], that seems to be part of a nearby stream of young stars known as the [AB Doradus Moving Group][1]. The researchers found the object in observations from the Canada-France-Hawaii Telescope and harnessed the power of ESO's Very Large Telescope to examine its properties [3].

The AB Doradus Moving Group is the closest such group to the Solar System. Its stars drift through space together and are thought to have formed at the same time. If the object is associated with this moving group -- and hence it is a young object -- it is possible to deduce much more about it, including its temperature, mass, and what its atmosphere is made of [4]. There remains a small probability that the association with the moving group is by chance.

The link between the new object and the moving group is the vital clue that allows astronomers to find the age of the newly discovered object [5]. This is the first isolated planetary mass object ever identified in a moving group, and the association with this group makes it the most interesting free-floating planet candidate identified so far.

"Looking for planets around their stars is akin to studying a firefly sitting one centimetre away from a distant, powerful car headlight," says Philippe Delorme (Institut de planetologie et d'astrophysique de Grenoble, CNRS/Universite Joseph Fourier, France), lead author of the new study. "This nearby free-floating object offered the opportunity to study the firefly in detail without the dazzling lights of the car messing everything up."

Free-floating objects like CFBDSIR2149 are thought to form either as normal planets that have been booted out of their home systems, or as lone objects like the smallest stars or brown dwarfs. In either case these objects are intriguing -- either as planets without stars, or as the tiniest possible objects in a range spanning from the most massive stars to the smallest brown dwarfs.

Tuesday, November 13, 2012

A previous, more taxonomic, approach to dinosaur ichnology focused on the collection and study of "museum grade" footprints which were used to identify dinosaur species and some of the individual dinosaur's physiological characteristics, such as size and mass.

Studies of the Broome dinosaur track way by palaeontologists McCrea, Lockley et al (2011), and Thulborn (2012), point to an emerging trend, the study of dinosaur interactions.

"Even poorly preserved prints can be useful for census purposes and for analysing foot/sediment interactions," says Indiana-Purdue University palaeontologist Prof James O. Farlow in his peer-review of the McCrea paper.

The Broome trackway was once an early Cretaceous shoreline, frequented by at least 15 dinosaur species that regularly walked in the moist intertidal sands and estuarine mud.

When conditions were right these solidified into sandstone, preserving footprints for posterity along much of the Dampier Peninsula's west coast.

The sandstone would then often be covered by further layers of sand on which dinosaurs, in turn, would leave more tracks.

As a result the Broome sandstone often comprises several layers of sediment, each containing underprints or "ghost prints".

"The patterns of deformation created by sauropods traversing thinly-stratified lagoonal deposits of the Broome Sandstone are unprecedented in their extent and structural complexity," Dr Thulborn says in his paper.

"The stacks of transmitted reliefs … beneath individual footfalls are nested into a hierarchy of deeper and more inclusive basins and troughs which eventually attain the size of minor tectonic features.

"Ultimately the sauropod trackmakers deformed the substrate to such an extent that they remodelled the topography of the landscape they inhabited.

"Such patterns of substrate deformation are revealed by investigating fragmentary and eroded footprints, not by the conventional search for pristine footprints on intact bedding planes.

"For that reason it is not known whether similar patterns of substrate deformation might occur at sauropod track-sites elsewhere in the world."

When looking for ways to reduce heat in lasers, PhD student Kathrin Sandner and Helmut Ritsch came up with a revolutionary idea: The theoretical physicists suggest using heat to power the laser. In their work, recently published in Physical Review Letters, the two physicists propose the theory that the heating effect in quantum cascade lasers could not only be avoided but, in fact, reversed through a cleverly-devised modification of the thickness of the semiconductor layers. "A crucial part is to spatially separate the cold and warm areas in the laser," explains Kathrin Sandner. "In such a temperature gradient driven laser, electrons are thermally excited in the warm area and then tunnel into the cooler area where photons are emitted." This produces a circuit where light particles are emitted and heat is absorbed from the system simultaneously. "Between the consecutive emissions of light particles a phonon is absorbed and the laser is cooled. When we develop this idea further, we see that the presence of phonons may be sufficient to provide the energy for laser amplification," says Kathrin Sandner. Such a laser could be powered without using electric current.

"Of course, it is quite a challenge to implement this concept in an experiment," says Helmut Ritsch. "But if we are successful, it will be a real technological innovation." The physical principle behind the idea could already be applied to existing quantum cascade lasers, where it could provide internal cooling. This simplified concept seems to be technically feasible and is already being examined by experimental physicists.

Monday, November 12, 2012

I was in the HPC world in 1995. It was a time of upheaval as many HPC computing companies were going out of business: the Cold War was over and they had by and large failed to find new sources of revenue than the US government (note: the US gov is STILL the largest source...as are govs around the world for other companies).

The United States will overtake Saudi Arabia and Russia as the world's top oil producer by 2017, the West's energy agency said on Monday, predicting Washington will come very close to achieving a previously unthinkable energy self-sufficiency.

The forecasts by the International Energy Agency (IEA), which advises large industrialized nations on energy policy, were in sharp contrast to previous IEA reports, which saw Saudi Arabia remaining the top producer until 2035.

"Energy developments in the United States are profound and their effect will be felt well beyond North America - and the energy sector," the IEA said in its annual long-term report, giving one of the most optimistic forecasts for U.S. energy production growth to date.

"The recent rebound in U.S. oil and gas production, driven by upstream technologies that are unlocking light tight oil and shale gas resources, is spurring economic activity - with less expensive gas and electricity prices giving industry a competitive edge," it added.

The IEA said it saw a continued fall in U.S. oil imports with North America becoming a net oil exporter by around 2030 and the United States becoming almost self-sufficient in energy by 2035.

"The United States, which currently imports around 20 percent of its total energy needs, becomes all but self-sufficient in net terms - a dramatic reversal of the trend seen in most other energy importing countries," it said.

IEA Chief Economist Fatih Birol told a news conference in London he believed the United States would overtake Russia as the biggest gas producer by a significant margin by 2015. By 2017, it would become the world's largest oil producer, he said.

The United States will rely more on natural gas than either oil or coal by 2035 as cheap domestic supply boosts demand among industry and power generators, the IEA said.

Real or the dangers of the linear extrapolating brain eater striking?

If this is the case, Global Warming Is Inevitable. cuz the junkie just got a new source for its fix.

Scientists have estimated that there are 1.7 million species of animals, plants and algae on earth, and new species continue to be discovered. Unfortunately, as new species are found, many are also disappearing, contributing to a net decrease in biodiversity. The more diversity there is in a population, the longer the ecosystem can sustain itself. Hence, biodiversity is key to ecosystem resilience.

Disease, destruction of habitats, pollution, chemical and pesticide use, increased UV-B radiation, and even the presence of new species are some of the causes for disappearing species. "Allee effect," the phenomenon by which a population's growth declines at low densities, is another key reason for perishing populations, and is an overriding feature of a paper published last month in the SIAM Journal on Applied Mathematics.

Authors Avner Friedman and Abdul-Aziz Yakubu use mathematical modeling to analyze the impact of disease, animal migrations and Allee effects in maintaining biodiversity. Some Allee effect causes in smaller and less dense populations are challenges faced in finding mating partners, genetic inbreeding, and cooperative behaviors such as group feeding and defense. The Allee threshold in such a population is the population below which it is likely to go extinct, and above which persistence is possible. Declining populations that are known to exhibit Allee effects currently include the African wild dog and the Florida panther.

Author Abdul-Aziz Yakubu explains how disease can alter the behavior of populations that exhibit Allee effects. In infectious disease studies, the reproduction number or Ro is defined as the expected number of secondary infections arising from an initial infected individual during the latter's infectious period. For regular populations, the disease disappears in the population if (and only if) the Ro is less than 1. "In the present paper, we deal with a population whose survival is precarious even when Ro is less than 1," says Yakubu. "That is, independent of Ro, if the population size decreases below a certain level (the Allee index), then the individuals die faster than they reproduce."

A previous study by the authors showed that even a healthy stable population that is subject to Allee effects would succumb to a small number of infected individuals within a single location or "patch," causing the entire population to become extinct, since small perturbations can reduce population size or density to a level below or close to the Allee threshold.

Transmission of infectious diseases through a population is affected by local population dynamics as well as migration. Thus, when trying to understand the resilience of the ecosystem, the global survival of the species needs to be taken into account, that is, how does movement of animals between different locations affect survival when a disease affects one or more locations? Various infectious disease outbreaks, such as the West Nile virus, Phocine and distemper viruses have been seen to spread rapidly due to migrations.

In this study, the authors extend their previous research by using a multi-patch model to analyze Allee effects within the context of migration between patches. "We investigate the combined effect of a fatal disease, Allee effect and migration on different groups of the same species," Yakubu says. In their conclusions, the host population is seen to become extinct whenever the initial host population density on each patch is lower than the smallest Allee threshold. When the initial host population has a high Allee threshold, the population persists on each patch if the disease transmission rates are small and the growth rate is large. Even in the case of high Allee thresholds, the host population goes extinct if the disease transmission rate is high, and growth rate and disease threshold are small. The presence of a strong Allee effect adds the possibility of population extinction even as the disease disappears.

South America has yielded abundant and diverse Early Cretaceous pterosaur remains, mainly from the highly productiveSantana Group (Aptian–Albian) in the Araripe Basin, northeastern Brazil (Kellner, 2001; Unwin and Martill, 2007). Several pterosaur taxa have been reported from these beds, including Tapejara, Tupuxuara, and Anhanguera as the most outstanding examples (Kellner, 2001). Another highly productive Lower Cretaceous South American pterosaur-bearing unit is the Lagarcito Formation (Albian) of central Argentina that has yielded a monospecific assemblage of the pterodactyloid Pterodaustro guinazui (Bonaparte, 1970; Chiappe et al., 1998; Codorni ´u and Gasparini, 2007). The La Amarga Formation (Barremian–early Aptian) in northwestern Patagonia has provided an isolated pterosaur femur (Montanelli, 1987) and the R´ıo Belgrano Formation (Barremian) in southern Patagonia has yielded an ulna and a probable partial wing metacarpal of a probable anhanguerid pteranodontoid (Kellner et al., 2003). In the Lower Cretaceous of Chile, a partial jaw with teeth and a proximal wing phalanx were assigned to an indeterminate ctenochasmatid (Martill et al., 2006). In addition, some fragmentary pterosaur remains have been reported from the Lower Cretaceous of Venezuela and Peru (Codorni ´u and Gasparini, 2007; Barrett et al., 2008). By contrast, the Late Cretaceous pterosaur bone record of South America is still scarce and restricted to a handful of fragmentary specimens, including remains referred to the nyctosaurid Nyctosaurus lamegoi from the Maastrichtian of Brazil (Price, 1953; Lima and Koutsoukos, 2006) and azhdarchoid long bones, probably from a taxon closely related to or a member of Azhdarchidae, from the Turonian–Coniacian Portezuelo Formation (Calvo and Lockley, 2001; Kellner et al., 2004, 2006; Apestegu´ıa et al., 2007; Codorni ´u and Gasparini, 2007).

Here, we expand the meager record of Late Cretaceous South American pterosaurs with the description of a partial rostrum belonging to a large azhdarchid pterodactyloid. The specimen was collected close to the Bajo de Arriagada locality, corresponding to the uppermost Cretaceous Allen Formation of Argentina, around 80 km northwest of the well-sampled Bajo de Santa Rosa locality (Martinelli and Forasiepi, 2004) (Fig. 1). The Azhdarchidae were the most abundant pterosaurs during latest Cretaceous times (Company et al., 1999; Butler et al., 2009). This clade comprises several species of long-necked pterosaurs ranging from 2.5 to 10 m in wing span, thus including the largest known flying vertebrates, such as the gigantic Quetzalcoatlus and Hatzegopteryx (Kellner and Langston, 1996; Buffetaut et al., 2002; Witton and Naish, 2008; Witton and Habib, 2010). Azhdarchid remains have been documented from almost all continental landmasses, including Europe, North America, Africa, Asia, and probably Oceania (Bennett and Long, 1991; Company et al., 1999; Averianov et al., 2005; Barrett et al., 2008; Kear et al., 2010; O˝ si et al., 2011). In South America, probable azhdarchid remains consist of a fragmentary postcranial skeleton from the Aptian of Brazil (Martill and Frey, 1998, 1999) and partial long bones from the Turonian–Coniacian of Argentina (Kellner et al., 2006; Codorni ´u and Gasparini, 2007). However, recent reassessments of this material suggested that the Brazilian specimen is more closely related to tapejarids than to azhdarchids and that the Argentinean records are dubious (Kellner, 2004; Kellner et al., 2006; Unwin and Martill, 2007). As a result, the specimen reported here represents the first unambiguous evidence of an azhdarchid pterosaur from South America. This specimen represents a new genus and species, Aerotitan sudamericanus, which is diagnosed based on a unique combination of characters, including one autapomorphy, and represents one of the largest known South American pterosaurs. The fossil here described resulted from a joint Argentine-Swedish paleontological expedition to Patagonia.

Climate model projections showing a greater rise in global temperature are likely to prove more accurate than those showing a lesser rise, according to a new analysis by scientists at the National Center for Atmospheric Research (NCAR). The findings, published in this week's issue of Science, could provide a breakthrough in the longstanding quest to narrow the range of global warming expected in coming decades and beyond.

NCAR scientists John Fasullo and Kevin Trenberth, who co-authored the study, reached their conclusions by analyzing how well sophisticated climate models reproduce observed relative humidity in the tropics and subtropics.

The climate models that most accurately captured these complex moisture processes and associated clouds, which have a major influence on global climate, were also the ones that showed the greatest amounts of warming as society emits more greenhouse gas into the atmosphere.

"There is a striking relationship between how well climate models simulate relative humidity in key areas and how much warming they show in response to increasing carbon dioxide," Fasullo says. "Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections."

[...]

The world's major global climate models, numbering more than two dozen, are all based on long-established physical laws known to guide the atmosphere. However, because these relationships are challenging to translate into software, each model differs slightly in its portrayal of global climate. In particular, some processes, such as those associated with clouds, are too small to be represented properly.

The most common benchmark for comparing model projections is equilibrium climate sensitivity (ECS), or the amount of warming that eventually occurs in a model when carbon dioxide is doubled over preindustrial values. At current rates of global emission, that doubling will occur well before 2100.

For more than 30 years, ECS in the leading models has averaged around 5 degrees Fahrenheit (3 degrees Celsius). This provides the best estimate of global temperature increase expected by the late 21st century compared to late 19th century values, assuming that society continues to emit significant amounts of carbon dioxide. However, the ECS within individual models is as low as 3 degrees F and as high as 8 degrees F, leaving a wide range of uncertainty that has proven difficult to narrow over the past three decades.

The difference is important to reconcile, as a higher temperature rise would produce greater impacts on society in terms of sea level rise, heat waves, droughts, and other threats.

Clouds are one of the main sticking points, say the NCAR authors. Although satellites observe many types of clouds, satellite failure, observing errors, and other inconsistencies make it challenging to build a comprehensive global cloud census that is consistent over many years.

However, satellites perform better in measuring water vapor, and estimates of the global distribution of relative humidity have become more reliable. Relative humidity is also incorporated in climate models to generate and dissipate clouds.

Fasullo and Trenberth checked the distribution of relative humidity in 16 leading climate models to see how accurately they portray the present climate. In particular, they focused on the subtropics, where sinking air from the tropics produce very dry zones where most of the world's major deserts are located.

The seasonal drying in the subtropics and the associated decrease in clouds, especially during May through August, serve as a good analog for patterns projected by climate models.

[...]

Estimates based on observations show that the relative humidity in the dry zones averages between about 15 and 25 percent, whereas many of the models depicted humidities of 30 percent or higher for the same period. The models that better capture the actual dryness were among those with the highest ECS, projecting a global temperature rise for doubled carbon dioxide of more than 7 degrees F. The three models with the lowest ECS were also the least accurate in depicting relative humidity in these zones.

"Because we have more reliable observations for humidity than for clouds, we can use the humidity patterns that change seasonally to evaluate climate models," says Trenberth. "When examining the impact of future increases in heat-trapping gases, we find that the simulations with the best fidelity come from models that produce more warming."

Astronomers have discovered a new super-Earth in the habitable zone, where liquid water and a stable atmosphere could reside, around the nearby star HD 40307. It is one of three new super-Earths found around the star that has three other low-mass planets orbiting it.

HD 40307 is a dwarf star that is somewhat smaller and less luminous than the Sun that is about 42 light years away (12.88 parsecs). The previously discovered planets around it are called hot super-Earths because they orbit too close to the star to support life.

The international team, including Carnegie co-author Paul Butler, was led by Mikko Tuomi of the University of Hertfordshire and Guillem Anglada-Escudé of the University of Göttingen. The researchers used newly developed software that is able to process the signals more thoroughly and thereby reveal the presence of the three additional planets. The team reanalyzed spectra taken with the HARPS spectrograph through the European Southern Observatory public archive.

Butler explained: "With Guillem Anglada-Escudé's new velocity reduction package, we are able to extract more information from the HARPS spectra, and thus make a more precise measurement. This coupled with the innovative Bayesian orbital searching algorithm, primarily written by Mikko Tuomi, allows us to search deeper into the data and to find smaller Earth-sized planets around the nearest stars. This, of course, increases our chances of finding more in that orbital sweet spot that we call the habitable zone—the zone where it is not too cold, nor too hot for liquid water to exist." Anglada-Escudé wrote the velocity reduction package while he was a postdoctoral fellow at Carnegie.

The most interesting of the new planets is in the outermost orbit from the star, a distance that is similar to the distance between the Earth and our Sun. Its mass is at least seven times the mass of the Earth. The team said the planet is likely to be rotating on its axis while in orbit, possibly creating a day/night cycle and an Earth-like environment.

HD 40307 is a K class star and 42 light years away. It has six planets that have been detected to date. G, appears to be in the habitability zone. the layout for a comparison with our own solar system is above from the paper.

Scientists have named a new species of horned dinosaur (ceratopsian) from Alberta, Canada. Xenoceratops foremostensis (Zee-NO-Sare-ah-tops) was identified from fossils originally collected in 1958. Approximately 20 feet long and weighing more than 2 tons, the newly identified plant-eating dinosaur represents the oldest known large-bodied horned dinosaur from Canada. Research describing the new species is published in the October 2012 issue of the Canadian Journal of Earth Sciences.

"Starting 80 million years ago, the large-bodied horned dinosaurs in North America underwent an evolutionary explosion," said lead author Dr. Michael Ryan, curator of vertebrate paleontology at The Cleveland Museum of Natural History. "Xenoceratops shows us that even the geologically oldest ceratopsids had massive spikes on their head shields and that their cranial ornamentation would only become more elaborate as new species evolved."

Xenoceratops (Xeno + ceratops) means "alien horned-face," referring to the strange pattern of horns on its head and the scarcity of horned dinosaur fossils from this part of the fossil record. It also honors the Village of Foremost, located close to where the dinosaur was discovered. Xenoceratops had a parrot-like beak with two long brow horns above its eyes. A large frill protruded from the back of its skull featuring two huge spikes.

"Xenoceratops provides new information on the early evolution of ceratopsids, the group of large-bodied horned dinosaurs that includes Triceratops," said co-author Dr. David Evans of the Royal Ontario Museum and University of Toronto. "The early fossil record of ceratopsids remains scant, and this discovery highlights just how much more there is to learn about the origin of this diverse group."

The new dinosaur is described from skull fragments from at least three individuals from the Foremost Formation originally collected by Dr. Wann Langston Jr. in the 1950s, and is currently housed in the Canadian Museum of Nature in Ottawa, Canada. Ryan and Evans stumbled upon the undescribed material more than a decade ago and recognized the bones as a new type of horned dinosaur. Evans later discovered a 50-year-old plaster field jacket at the Canadian Museum of Nature containing more skull bones from the same fossil locality and had them prepared in his lab at the Royal Ontario Museum.

Wednesday, November 07, 2012

Humans share over 90% of their DNA with their primate cousins. The expression or activity patterns of genes differ across species in ways that help explain each species' distinct biology and behavior.

DNA factors that contribute to the differences were described on Nov. 6 at the American Society of Human Genetics 2012 meeting in a presentation by Yoav Gilad, Ph.D., associate professor of human genetics at the University of Chicago.

Dr. Gilad reported that up to 40% of the differences in the expression or activity patterns of genes between humans, chimpanzees and rhesus monkeys can be explained by regulatory mechanisms that determine whether and how a gene's recipe for a protein is transcribed to the RNA molecule that carries the recipe instructions to the sites in cells where proteins are manufactured.

In addition to improving scientific understanding of the uniqueness of humans, studies such as the investigation conducted by Dr. Gilad and colleagues could have relevance to human health and disease.

"Through inter-species' comparisons at the DNA sequence and expression levels, we hope to identify the genetic basis of human specific traits and in particular the genetic variations underlying the higher susceptibility to certain diseases such as malaria and cancer in humans than in non-human primates," said Dr. Gilad.

They found that the distinct gene expression patterns of the three species can be explained by corresponding changes in genetic and epigenetic regulatory mechanisms that determine when and how a gene's DNA code is transcribed to a messenger RNA (mRNA) molecule.

Dr. Gilad also determined that the epigenetics process known as histone modification also differs in the three species. The presence of histone marks during gene transcription indicates that the process is being prevented or modified.

"These data allowed us to identify both conserved and species-specific enhancer and repressor regulatory elements, as well as characterize similarities and differences across species in transcription factor binding to these regulatory elements," Dr. Gilad said.

Among the similarities among the three species were the promoter regions of DNA that initiated transcription of a particular gene.

In all three species, Dr. Gilad's lab found that transcription factor binding and histone modifications were identical in over 67% of regulatory elements in DNA segments that are regarded as promoter regions.

(Miocene carnivores of Florida, similar, but not the same as below. img credit)

The fossilized fangs of saber-toothed cats hold clues to how the extinct mammals shared space and food with other large predators 9 million years ago.

Led by the University of Michigan and the Museo Nacional de Ciencias Naturales in Madrid, a team of paleontologists has analyzed the tooth enamel of two species of saber-toothed cats and a bear dog unearthed in geological pits near Madrid. Bear dogs, also extinct, had dog-like teeth and a bear-like body and gait.

The researchers found that the cat species—a leopard-sized Promegantereon ogygia and a much larger, lion-sized Machairodus aphanistus—lived together in a woodland area. They likely hunted the same prey—horses and wild boar. In this habitat, the small saber-toothed cats could have used tree cover to avoid encountering the larger ones. The bear dog hunted antelope in a more open area that overlapped the cats' territory, but was slightly separated.

"These three animals were sympatric—they inhabited the same geographic area at the same time. What they did to coexist was to avoid each other and partition the resources," said Soledad Domingo, a postdoctoral fellow at the U-M Museum of Paleontology and the first author of a paper on the findings published in the Nov. 7 edition of Proceedings of the Royal Society B.

Millions of years before the first humans, the predators lived during the late Miocene Period in a forested area that had patches of grassland. Large carnivores such as these are rare in the fossil record, primarily because plant-eating animals lower on the food chain have outnumbered meat-eaters throughout history.

Cerro de los Batallones, where Domingo has been excavating for the past eight years, is special. Of its nine sites, two are ancient pits with an abundance of meat-eating mammal bones. Agile predators, the researchers say, likely leapt into the natural traps in search of trapped prey.

"These sites offer a unique window to understand life in the past," Domingo said.

To arrive at their findings, the researchers conducted what's called a stable carbon isotope analysis on the animals' teeth. Using a dentist's drill with a diamond bit, they sampled teeth from 69 specimens, including 27 saber-toothed cats and bear dogs. The rest were plant-eaters. They isolated the carbon from the tooth enamel. Using a mass spectrometer, which you could think of as a type of scale, they measured the ratio of the more massive carbon 13 molecules to the less-massive carbon 12. An isotope is a version of an element that contains a different number of neutrons in its nucleus.

[..]

Because the researchers can tell what the herbivores ate, they can surmise what their habitat was like. They believe the animals in this study lived in a wooded area that contained patches of grassland.

The cats showed no significant difference in their stable carbon isotope ratios. That means they likely fed on the same prey and lived in the same habitat, but the posits that the species each fed on different-sized prey.

[...]

"The three largest mammalian predators captured prey in different portions of the habitat, as do coexisting large predators today. So even though none of the species in this 9-million year old ecosystem are still alive today (some of their descendants are), we found evidence for similar ecological interactions as in modern ecosystems," said Catherine Badgley, co-author of the new study and assistant professor of ecology and evolutionary biology.